Draft limiting damper



y 1, 1950 E. A. FIELD, JR 2,514,446

- DRAFT LIMITING DAMPER Filed Feb. 28, 1947 INVENTOR.

l7 TTORNEX Patented July 11, 1950 UNITED STATES PATENT OFFICE DRAFTLIMITING DAMPER T Edward A. Field,-Jr., Mendota, Ill. ApplicationFebruary 28, 1947, Serial No. 731,592

15 Claims. (Cl. 236-45) This invention relates to improvements indraftlimiting damper.

The main objects of this invention are:

First, to provide an improved barometric draft control which may bemanually actuated to hold it in open position under certain conditions,for example, when it is desired to bank or check the fire in a furnaceto which the control is applied. Second, to provide a draft control ofthis character which may be very economically produced and may bereadily installed and also one in which the parts are so arranged thatthe gate and its supports cannot be injured in the event of excessiveforce being applied-to the manual control.

Third, to provide a draft control in which the gate or damper may beheld in open position by means of a remote control such, for example, asa. chain or cable; also being operatively connected to an ashpit draftdoor or, alternately, may be actuated by a thermostat and damper motor.

Fourth, to provide a draft control of this type which maybe assembled asa unit and readily installed in a furnace.

Objects relating to details and economies of the invention will appearfrom the-description to follow. The invention is definedand pointed outin the claims. I

A preferred embodiment of the invention is illustrated in theaccompanyingdrawings, in which:

Fig. 1 is a side elevational view of a furnace mainly shownconventionally with the draft control of the inventioninstalled in theflue thereof.

Fig. 2 is a, front elevational view. of the control with portions brokenaway andother portions shown conventionally. I Fig. 3 is a fragmentaryview mainly in vertical section on the broken line 3-3 of Fig. 2, thegate being shown in closed position by full lines and in partially openposition by dotted lines.

Fig. 4 is a fragmentary elevational view showing structural details.

Fig. 5 is a fragmentary view in horizontal section on a linecorresponding to line 55 of Fig. 2.

In the accompanying drawings, 1 represents a furnace, 2 the chimney,'and3 the flue which is provided with a laterally projecting housing 4 6 atits outer end which serves as a locating means and also as a reinforcingmeans for the frame which is desirably formed as a sheet metal stamping.l

The gate frame is providedwith" an inwardly 2 projecting flange 1' atits inner edge, this flange having'segmerital enlargedv portions 8 onopposite sides thereof, these segmentalportions 8 having inwardlyprojecting Wings 9 extending from their edges. These wings are in spacedparallel relation to receive the gate it between them.

The gate swings between the wings which serves to substantially reduceor minimize the passage of" air around the sides of the gate, thusproviding a much more uniform control or regulation than would bepossible without the wings.

The gate is provided with a pintle or pivot rod ll arrangedsubstantially below the center of the gate. The wings are provided withbearing openings I2 of substantial size so that the pintle or pivot mayhave rolling engagement with the bottom. edges [3 thereof.

The pintle is secured to the rear side of the gate by'm'eans of a plateM having a longitudinal groove I5 in its front side, the groove beingformed by a longitudinal corrugation It in the plate.

The plate has upwardly projecting ears I! and f8 receiving the rivets Itfor clampingly securing the pivot with .its ends projecting intoengagementwith the bearing surfacesv l6. To provide a stop for limitingthe rearward swinging movement of the gate, the ear N3 of the pivotplate is provided with a rearwardly and laterally projecting angular arm20 which extends throughv an opening 2| in one of the wings 9, see Fig.3, the stop arm serving to limit the forward movement Of the gate asshown by full lines in Fig. 3 as well .as its'rearward tilting movementas shown by dotted lines at 22, Fig. 3.

The screw 23 is provided for clamping the frame within the housing 4.The counterweight arm 24 is provided with an adjustable weight 25 andprojects through the gate which is offset at 26 so that the arm is inthe desired angular relation to the gate.

The balancing weight 21 is threaded upon the rear end of the threadedarm 24. The weight 25 is adjustable to provide suitable barometriccontrol. A supplementary disk-like weight 28 is mounted by the screw 29above the pivot and on the rear Side of the gate, this being adjustableto accurately counterbalance the gate and it is not intended-that thisshall be adjusted for barometric control once the gate is properlybalanced, desirably at the factory.

In operating a furnace, there are certain conditions where it isdesirable to prevent or eliminate the barometric action of the gate-forexample, when it is desired to bank or check the fire in the furnace towhich the control is applied. To this end, I provide a control leverdesignated generally by the numeral 30 and comprising a pivot portion 3I, an arm 32 at the inner end of the pivot portion adapted to engage thefront of the gate and a downwardly and forwardly projecting actuatingarm 33 at the other end of the pivot. The lever is mounted on a bracket34 secured to the front side of one of the segments 8 of the inwardlyprojecting frame flange. This bracket is formed as a sheet metalstamping and has a knuckle portion 35 at its lower edge receiving thepivot of the lever and a 1 laterally projecting stop 36 limiting thereturn movement of the lever under the action of the weight 31. Thisweight is desirably formed as a flat stock or as a stamping and hasaneye 38 at its upper end engaging the eye 33 on the outer end of thearm 33. Desirably the eye 38 is formed by transversely slotting theweight at its upper end as is indicated by dotted lines in Fig. 2 andafter the hook'part 40 is passed through the eye of the lever it isclamped down to the position shown by dotted lines.

The lever is actuated by a chain or cable 4! extending over suitableguide pulleys 42, the chain 4| being preferably operatively associatedwith the chain 43 arranged over the guide pulley 44, the chainsextending to a remote control station to be manually operated or to beactuated by a thermostatically controlled motor.

It will of course be appreciated that the lever 30 may be controlledentirely independently of the draft if that is desired. The lever isdesirably formed of wire which not only results in a light economicalstructure but the wire is desirably of such gauge that it will bend andprevent the gate or its pivots being distorted or damaged by excessivepull on the cable 4|. The lever is carried by the frame and is mountedwithin the frame so that it is fully protected thereby.

I have illustrated and described a highly practical embodiment of theinvention. I have not attempted to illustrate or describe otherembodiments or adaptations as it is believed that this disclosure willenable those skilled in the art to embody or adapt the invention as maybe desired.

Having thus described my invention, what I claim as new and desire tosecure by Letters Patent, is:

1. In a draft control, a cylindrical housing, an annular gate framedisposed within said housing and having an out-turned outer flange onits front edge engaging the end of the housing and provided with aninturned flange at its inner end defining a gate opening having opposedsegmental side portions, wings integral with said frame projectingrearwardly from the edges of said segmental side portions and havingpintle openings therein, a gate dimensioned to swing within said frameopening and between said wings, a pintle, a pintle supporting platehaving a longitudinal corrugation receiving said pintle, said platebeing secured on the rear side of said gate and having a rearwardly andlaterally projecting stop arm at one end thereof, the. adjacent wingbeing provided with an opening, the opposed edges of which constitutestops for limiting the swinging movement of the gate, the gate beingsubstantially balanced in closed position and weighted for barometricdraft control, means for holding said gate in an open position againstthe return action of its weight comprising a lever pivotally mountedwithin said gate frame to engage said gate, and. remote control meansfor said lever.

2. In a draft control, a housing, a gate frame disposed within saidhousing and provided with an inturned flange at its inner end defining agate opening having opposed segmental side portions, wings integral withsaid frame projecting rearwardly from the edges of said segmental sideportions and having pintle openings therein, a gate dimensioned to swingwithin said frame opening and between said wings, a pintle, and a pintlesupporting plate having a longitudinal corrugation receiving saidpintle, said plate being secured on the rear side of said gate andhaving a rearwardly and laterally projecting stop arm at one endthereof, the adjacent wing being provided with an opening, the opposededges of which constitute stops for limiting the swinging movement ofthe gate, the gate being substantially balanced in closed position andWeighted for barometric draft control.

3. In a draft control, a housing, a gate frame disposed within saidhousing and provided with an inturned flange at its inner end defining agate opening having opposed segmental side portions, wings integral withsaid frame projecting rearwardly from the edges of said segmental sideportions and having pintle openings therein, a gate dimensioned to swingwithin said frame opening and between said wings, a pintle, a pintlesupporting plate having a longitudinal corrugation receiving saidpintle, said plate being secured on the rear side of said gate andhaving a rearwardly and laterally projecting stop arm at one endthereof, the adjacent wing being provided with an opening, the opposededges of which constitute'stops for limiting the swinging movement ofthe gate, the gate being substantially balanced in closed position andweighted for barometric draft control, means for holding said gate in anopen position against the return action of its weight comprising a leverpivotally mounted within said gate frame to engage said gate, and remotecontrol means for said lever.

4. In a draft control, a housing having an open outer end, agate framedisposed within said housing and having a gate opening spaced inwardlyfrom the open outer end of the housing and having rearwardly projectingwings at opposite sides of its gate opening, said wings having pintleopenings therein, a gate dimensioned to swingwithin said frame openingbetween said wings, a pintle secured to said gate and projecting intosaid pintle openings, said gate having a laterally projecting stop arm,the adjacent wing being provided with an opening, edges of whichconstitute stops for engaging said stop arm for limiting the swingingmovement of the gate, the gate being weighted for barometric draftcontrol, means for holding said gate in an open position against thereturn action of its weight comprising a lever pivotally mounted withinsaid gate frame and inrearwardly spaced relation from the open outer endof said housing and closely adjacent the pivotal axis of the gate, saidlever including a gate engaging arm disposed substantially parallel tothe plane of the gate when the gate is in closed position, and remotecontrol means for said lever.

5. In a draft control, a housing, a gate frame disposed within saidhousing and having rearwardly projecting wings at opposite sides of itsgate opening, said wings having pintle openings therein, a gatedimensioned to swing within said frame opening between said wings, apintle projecting into said pintle openings, and a pintle supportingplate for securing said pintle to said gate, said plate having alaterally projecting stop arm integral therewith, said pintlebeingdisposedbetween said plate'and gate, said plate being fixedly secured tothe gate between the pintle .and stop arm, the adjacent wing beingprovided with an opening, edges of which constitute stops for engagingsaid stop-arm for limiting the swinging movement of the gate, the gatebeing weighted for barometric 1 draft control.

6. In a draft control, a housing, a gate frame disposed within saidhousing and rhavingat' its inner end an'inturned flange andrsegmentalside portions and havingwings'projecting rearwardly from said segmentalside portions at opposite sides of its gate opening;said'wings havingpintle openings therein, a, gate dimensioned to swing within said frameopeningbetween said wings,

.a pintle, a pintle'supporting..plate, said atehaving a laterallyprojecting stop arm, the adjacent wing being provided. with an opening,edges of which constitute stops for limiting the swinging movement ofthe gate, the gate being weighted for barometric draft control, meansfor holding said, gate in an open position against the return action ofits weight comprising a lever including a pivot portionandv gate,engaging arm at the inner end of the pivot portion and an actuating armat the outer end thereof, a supporting bracket for said lever mountedupon the front side of one of the segmental side portions and having apivot knuckle at its lower end receiving and having a'forwardly offsetlever stop arm projecting into the-path-of said gate actuating arm, saidlever being supportedwithin said gate frame with the end of itsactuating arm projecting forwardly beyond the front edge of the frame,and a cable connected to said actuating arm.

7. In a draft control, a housing, an annular gate frame disposed withinsaid housing and provided with an inwardly projecting flange defining agate opening and having opposed segmental side portions, a gate, apintle for said gate carried by said frame, said gate being weighted forbarometric draft control, and means for holding said gate in an openposition against the return action of its weight comprising a lever, asupporting bracket for said lever on which said lever is pivoted mountedupon the front side of one of the segmental side portions of said flangeand having a lever stop arm projecting into the path of said gateactuating arm, said lever being supported within said gate frame withthe end of its actuating arm projecting forwardly, and a cable connectedto said actuating arm.

8. In a draft control, a housing, an annular gate frame disposed withinsaid housing and provided with an inwardly projecting flange defining agate opening and having opposed segmental side portions, a gate, apintle for said gate carried by said frame, said gate being weighted forbarometric draft control, and means for holding said gate in an openposition against the return action of its weight comprising a leverincluding a pivot portion and gate engaging arm at the inner end of thepivot portion and an actuating arm at the outer end thereof, asupporting bracket for said lever on which said lever is pivoted mountedupon the front side of one of the segmental side portions and having alever stop arm projecting into the path of said gate actuating arm, saidlever being supported within said gate frame with the end of itsactuating arm projecting forwardly, a cableconnected to said actuatingarm, and a weight at the outer end of said actuating armacting tonormally hold's'aid lever in retracted position against said stop and toapply return pull stress to the cable.

9'. In a draft control, a housing, a gateZframe disposedtwithin saidhousingand defining a ate opening, a gate pivotally mounted within saidframe and weighted forlcbarometricdraft control, and means forholding'said'gate in open position against the return action of itsweight comprising a lever-formed-of wire and including a pivotportionand a gate engaging arm at-the inner end of the pivot .portion and anactuating arm atvthe outer end thereof projecting forwardly from saidframe, a sheet metal member on said gateframe provided with an outwardlyprojecting offset portion for receiving said pivot-portion of saidlever, a cable connected to said actuating arm, and a weight operativelyassociated with said actuating'arm and acting to normally hold saidlever in retracted position, said lever beingof relatively lightwire'stock' so that it'will spring or bend under such stress asmight'distort the gate or its mounting.

10. In a draft control, a housing,a gate frame disposed within saidhousing and defining a gate opening, a gate pivotally mounted withinsaid frame and weighted for barometric draft control, and means forholding said gate in' open position against the return action of itsweight comprising a, lever formed of wire and including a-pivotzportionand-a gate engaging arm at'the inner end of the pivot portion and anactuating arm at the outer end thereof projecting forwardly from saidframe, a sheet metal member on said gate frame provided with anoutwardly projecting ofiset portion for receiving said pivot portion ofsaid lever, and a cable connected to said actuating arm, said leverbeing of relatively light wire stock so that it will spring or bendunder such stress as might distort the gate or its mounting.

11. In a draft control, a housing, a gate frame disposed within saidhousing and defining a gate opening, a gate pivotally mounted withinsaid frame for movement of the upper portion of the gate inwardly andweighted for barometric draft control, and means for holding said gatein open position against the return action of its weight comprising alever pivoted at the side of the gate frame intermediate the top and thebottom thereof and having an arm for engaging the gate above the pivotthereof and having an actuating arm projecting forwardly from saidframe, said lever being formed of resilient relatively light wire stockbent to provide said gate engaging and actuating arms and a relativelylong pivot portion intermediate said arms, means on the gate frame forpivotally supporting said lever pivot portion intermediate said arms, acable connected to said actuating arm, and a weight operativelyassociated with said actuating arm and acting to normally hold saidlever in retracted position.

12. In a draft control, a housing, a gate frame disposed within saidhousing defining a gate opening and having opposed segmental sideportions, a gate, a pintle for said gate carried by said frame, saidgate being weighted for barometric draft control, a lever supportingbracket mounted on one of said frame side segments, a lever pivotallymounted on said bracket and comprising a gate engaging arm disposed infront of the gate and an actuating arm disposed closely to the frame andlying mainly normally within the frame, saidbracket ,being provided witha stop arm projecting into the path of the gate actuating arm, a remotecontrol connected to said actuating arm, and a weight operativelyassociated with said actuating arm to normally hold the lever inretracted position against said stop, said lever being of relativelylight stock so that it will bend or spring under such stress as mightdistort the gate or its mounting.

13. In a draft control, a housing, a gate frame disposed within saidhousing defining a gate opening, a gate, a pintle for said gate carriedby said frame, said gate being weighted for barometric draft control, alever supporting bracket mounted within said frame, a lever pivotallymounted on-said bracket and comprising a gate engaging arm disposed infront of the gate and 'an actuating arm disposed closely 'tothe frameand'lying mainly normally'within the frame, said bracket being providedwith a stop arm projecting into'the path of the gate actuating arm, aremote control connected to said actuating arm, and a weightoperativelyassociated with said actuating arm to normally hold the leverin retracted position against said stop, said lever being of relativelylight stock so that it will bend or spring under such stress as mightdistort the gate or its mounting.

14. In a draft control, a housing, a gate frame disposed within saidhousing defining a gate opening, a gate, a pintle for said gatejournaled on said frame, said gate-being weighted for barometric draftcontrol, a lever supporting bracket mounted within said frame, a leverpivot-ally mounted on said bracket and comprising a gate engaging armdisposed in front of the gate and an actuating arm disposed closely tothe frame and lying mainly normally within the frame, said bracket beingprovided with a stop arm projectinginto the path of the gate actuatingarm, and a remote control connected to said actuating arm.

15. In a draft control, a housing, a gate frame disposed within saidhousing and defining a gate opening, a gate pivotally mounted withinsaid frame for movement'of the upper portion of the gate inwardly, saidgate being weighted for barometric draft control, a lever pivotallymounted on said frame at one side of the frame andintermediate the topand bottom thereof and having a gate engaging arm and an actuating'armprojecting forwardly, said gate engaging arm'being disposed to engagethe gate above the pivot thereof, said lever being formed of resilientrelatively light wire stock bent to provide said gate engaging andactuating arms and a relatively long pivot portion intermediate saidarms, means on the gate frame for pivotally supporting said lever pivotportion intermediate saidarms, a remote control connected to saidactuating arm, and means associated with said lever for normally holdingit in retracted position. a

. EDWARD A. FIELD, 'JR.

REFERENCES CITED The following references 'are of record in th file ofthis patent: r

UNITED STATES PATENTS;

Crew June 4, 1946

